USM Test Cryostat for the MICADO project: first steps in stabilizing and testing the cryostat

We present the new LN2 continuous- ow test cryostat of the Universitats-Sternwarte Munchen, procured within the context of the Multi-Adaptive Optics Imaging Camera for Deep Observations (MICADO) for the Extremely Large Telescope. The cryostat will be used to perform tests of mechanical, optical and electronic components at high vacuum condition and cryogenic temperature, for the development of the cryogenic Main Selection Mechanism of the MICADO instrument. In this paper we give an overview of the cryostat design and we report about the temperature stability the cryostat can achieve, as well as the temperature gradient over its cold plate. We also report about the impact of adding extra loads on the system after integrating a cold curved shutter in the cryostat and on characterizing the thermal coupling of cryogenic assemblies.